Figure 6

YY1 overexpression suppresses HS578T cell migration in vitro. (a) HS578T cells were transiently transfected with either an empty vector (CMV-empty) or a vector expressing HA-tagged ying yang 1 (YY1; CMV-YY1). Seventy-two hours later the cells were used in migration assays using 5% fetal bovine serum as a chemoattractant. Membranes were stained with crystal violet and the stain was eluted with 10% acetic acid. The eluate was read at OD₆₀₀. (b) The transfected HS578T cells were also used for in vitro matrigel invasion assays. Membranes were stained with crystal violet. Eight to ten high power fields (HPF; 200× magnification) were counted for each membrane and averaged. (c) An equal number of HS578T cells used for migration and invasion assays were boiled in SDS sample buffer, and an equal volume of each was run on an SDS-PAGE gel. Note that the upper band of the doublet in the YY1 panel represents the HA-tagged species, and the lower band represents endogenous YY1. No difference in HP1α expression was observed after 72 hours of YY1 overexpression. β-tubulin was included as a loading control.